Depends on what is meant by "legal". Strictly speaking nitrous oxide is "legal", meaning that if you buy a bunch of whipped cream cans (two of them have enough gas to fill a single standard balloon, the standard-size "hit") you are technically having a "legal high". Since all you want is the nitrous oxide propellant, buy the cheapest whipped cream. To avoid aspirating whipped cream into your lungs, let the cans sit outside the fridge for several hours to allow the cream to settle. And in answer to your question, "whipped cream nitrous oxide" is *very* good. Morning glory seeds (provided you don't use the poisonous recipe in the Anarchists Cookbook) don't provide that much of a high. Lysergic acid amide (LSA, the hallucinogen in morning glory seeds) isn't as nice as Lysergic acid diethylamide (LSD) and LSA always gave me a headache during the trip. Plus you have to grind up and consume a lot of them, which means using honey as a mixing agent to alleviate the resulting nausea. Kava Kava is a "dietary supplement" which is most often used as a muscle relaxant (and from personal experience it works very well in that regard, especially for my back pain) but it also gets you very high. Kava Kava has been directly linked to causing problems with the liver, so you should start taking Milk Thistle for your liver if you ever start taking Kava Kava on a regular basis. The Valerian root "dietary supplement" is an alternative to Valium and Xanax, so you can get an equivalent high to those drugs. Do remember that about 10% of the world's population has a stimulant reaction to Valerian, meaning it will sober that 10% up rather than causing a high. There are cooking seasonings which, when used in their raw form (i.e., something you just picked off the plant) can be hallucinogenic, but I'm not going to mention them here because their hallucinogenic dose levels are all very close to their lethal dose levels. There is one kitchen seasoning which is very good if you get the dosage just right, and I used it successfully as part of an ancient Mayan spiced chocolate drink (warning: the ancient Mayans preferred their chocolate completely unsweetened). EDIT: Okay, for the downrater who is so strung out they downrated me for not mentioning the cooking seasoning which is a hallucinogen, here's an esoteric hint: on the Food Network cooking show "Good Eats", chef Alton Brown, during one of his shows, mentioned (probably jokingly) that he "always carries one [of the seasoning] in his pocket, just in case."